I have a IBM Thinkpad T43, currently running Windows XP. Programs were crashing, XP was blue-screen-of-deathing, (more than usual) - it was basically unusable, but I couldn't get any informative error out of XP. I booted Ubuntu off a thumbdrive, which made it to the desktop, but as soon as I started to try to do anything, X segfaulted, along with several other services, followed quickly by kernel warnings and a kernel panic.

I'm currently running Memtest86+ on this machine, which is spitting out numerous errors. (16k over 3 passes, and counting) The failing areas are numerous, and look something like this:

0001055da4 - XX.X MB, etc.

The addresses that fail seem to cluster around 0-20 MB, 250MB, and, more rarely, 750MB, 1000MB, and 1200MB. However, a lot (but not all) of the failing addresses that I've seen end in XXXXXXX?da4 where the ? is a 1 or a 5.

The machine has two sticks of RAM, one 512MB, one 1024 MB, the 512MB mapped to the lower addresses, the 1024 MB stick following.

Is this indeed RAM failure, or should I consider other things before purchasing more RAM?